This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Births to American women 13 to 19 years of age are accompanied by poor fetal outcomes, including low birth-weight, unexplained by poor socio-economic factors. Conflicting data and mechanistic hypotheses have been proposed as explanations for these observations. Some human studies implicate continuing maternal growth in competition with fetal nutritional requirements as causal while others cite such competition as a positive condition for fetal growth. We are requesting the use of baboons, 4.5 y to 6 years of age, to test the hypothesis that placental and fetal growth and function are impaired in primiparous adolescent baboon pregnancies. We will fully characterize maternal body weights, fetal body and organ weights and IGF family peptide expression (IGF-I, IGF-R1 etc.) in peripheral plasma and selected fetal tissues, e.g. fetal liver and pancreas etc.